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mced.c
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/*
* mced.c - MCE daemon.
*
* Based on code from acpid.
* Copyright (c) 2007 Tim Hockin ([email protected])
* Copyright (c) 2007 Google, Inc. ([email protected])
* Portions Copyright (c) 2004 Tim Hockin ([email protected])
* Portions Copyright (c) 2001 Sun Microsystems
* Portions Copyright (c) 2000 Andrew Henroid
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/poll.h>
#include <grp.h>
#include <syslog.h>
#include <stdarg.h>
#include <sys/ioctl.h>
#include <sys/utsname.h>
#include "mced.h"
#include "cmdline.h"
#if ENABLE_MCEDB
#include "mcedb.h"
#endif
#if ENABLE_DBUS
#include "dbus.h"
#endif
#include "ud_socket.h"
/* global debug level */
int mced_debug_level;
/* do we log event info? */
int mced_log_events;
/* the number of non-root clients that are connected */
int mced_non_root_clients;
/* the size of a kernel MCE record in bytes */
size_t mced_kernel_record_len;
#if ENABLE_MCEDB
/* global database handle */
struct mce_database *mced_db;
#endif
/* statics */
static const char *progname;
static cmdline_int bootnum = -1;
static cmdline_int debug_level = 0;
static cmdline_bool log_events = 0;
static cmdline_string confdir = MCED_CONFDIR;
static cmdline_string device = MCED_EVENTFILE;
static cmdline_int max_interval_ms = MCED_MAX_INTERVAL;
static cmdline_int min_interval_ms = MCED_MIN_INTERVAL;
static cmdline_int mce_rate_limit = -1;
static cmdline_string socketfile = MCED_SOCKETFILE_V2;
static cmdline_string socketfile_compat = NULL;
static cmdline_bool nosocket = 0;
static cmdline_string socketgroup = NULL;
static cmdline_mode_t socketmode = MCED_SOCKETMODE;
static cmdline_bool foreground = 0;
static cmdline_string pidfile = MCED_PIDFILE;
static cmdline_int clientmax = MCED_CLIENTMAX;
static cmdline_int overflow_suppress_time = MCED_OVERFLOW_SUPPRESS_TIME;
static cmdline_bool retry_mcelog = 0;
#if ENABLE_MCEDB
static cmdline_string dbdir = MCED_DBDIR;
#endif
#if ENABLE_DBUS
static cmdline_bool no_dbus = 0;
static cmdline_bool use_session_dbus = 0;
#endif
static int mcelog_poll_works = 0;
static int log_is_open = 0;
static int fake_dev_mcelog = 0;
static enum {
KERNEL_MCE_UNKNOWN = 0,
KERNEL_MCE_V1, /* the historical 'struct mce' layout */
KERNEL_MCE_V2, /* 2.6.31 made 'struct mce' changes */
} kernel_mce_version;
/*
* Helpers
*/
static void do_help(const struct cmdline_opt *, ...);
static void do_version(const struct cmdline_opt *, ...);
static struct cmdline_opt mced_opts[] = {
#if ENABLE_MCEDB
{
"B", "dbdir",
CMDLINE_OPT_STRING, &dbdir,
"<dir>", "Set the database directory"
},
#endif /* ENABLE_MCEDB */
{
"d", "debug",
CMDLINE_OPT_COUNTER, &debug_level,
"", "Increase the debugging level (implies -f)"
},
{
"f", "foreground",
CMDLINE_OPT_BOOL, &foreground,
"", "Run in the foreground"
},
{
"b", "bootnum",
CMDLINE_OPT_INT, &bootnum,
"<num>", "Set the current boot number"
},
{
"c", "confdir",
CMDLINE_OPT_STRING, &confdir,
"<dir>", "Set the configuration directory"
},
{
"D", "device",
CMDLINE_OPT_STRING, &device,
"<file>", "Use the specified mcelog device"
},
{
"R", "retrydev",
CMDLINE_OPT_BOOL, &retry_mcelog,
"", "Retry the mcelog device if it fails to open"
},
{
"p", "pidfile",
CMDLINE_OPT_STRING, &pidfile,
"<file>", "Use the specified PID file"
},
{
"l", "logevents",
CMDLINE_OPT_BOOL, &log_events,
"", "Log each MCE and handlers"
},
{
"n", "mininterval",
CMDLINE_OPT_INT, &min_interval_ms,
"<num>", "Set the MCE polling min interval (in msecs)"
},
{
"x", "maxinterval",
CMDLINE_OPT_INT, &max_interval_ms,
"<num>", "Set the MCE polling max interval (in msecs)"
},
{
"r", "ratelimit",
CMDLINE_OPT_INT, &mce_rate_limit,
"<num>", "Limit the number of MCEs handled per second"
},
{
"o", "oflowsuppress",
CMDLINE_OPT_INT, &overflow_suppress_time,
"<num>", "Set the log period for overflows (in secs)"
},
{
"s", "socketfile",
CMDLINE_OPT_STRING, &socketfile,
"<file>", "Use the specified socket file"
},
{
"S", "nosocket",
CMDLINE_OPT_BOOL, &nosocket,
"", "Don't listen on a UNIX socket (overrides -s)"
},
{
"g", "socketgroup",
CMDLINE_OPT_STRING, &socketgroup,
"<group>", "Set the group on the socket file"
},
{
"m", "socketmode",
CMDLINE_OPT_MODE_T, &socketmode,
"<mode>", "Set the permissions on the socket file"
},
{
"C", "clientmax",
CMDLINE_OPT_INT, &clientmax,
"<num>", "Limit the number of non-root socket clients"
},
{
"O", "oldsocket",
CMDLINE_OPT_STRING, &socketfile_compat,
"", "Use the specified v1-compatible socket file"
},
#if ENABLE_DBUS
{
NULL, "no-dbus",
CMDLINE_OPT_BOOL, &no_dbus,
"", "Don't send MCEs over D-Bus"
},
{
NULL, "dbus-session-bus",
CMDLINE_OPT_BOOL, &use_session_dbus,
"", "Use D-Bus session bus, instead of system bus"
},
#endif
{
"v", "version",
CMDLINE_OPT_CALLBACK, do_version,
"", "Print version information and exit"
},
{
"h", "help",
CMDLINE_OPT_CALLBACK, do_help,
"", "Print this help message and exit"
},
CMDLINE_OPT_END_OF_LIST
};
/*
* Print usage info.
*/
static void
usage(FILE *out)
{
const char *help_str;
fprintf(out, "Usage: %s [OPTIONS]\n", cmdline_progname);
fprintf(out, "\n");
while ((help_str = cmdline_help(mced_opts))) {
fprintf(out, " %s\n", help_str);
}
fprintf(out, "\n");
}
/*
* Parse command line arguments.
*/
static int
handle_cmdline(int *argc, const char ***argv)
{
/* Parse the command line. */
if (cmdline_parse(argc, argv, mced_opts) != 0) {
usage(stderr);
exit(EXIT_FAILURE);
}
if (*argc != 1) {
fprintf(stderr,
"Unknown command line argument: '%s'\n\n", (*argv)[1]);
usage(stderr);
exit(EXIT_FAILURE);
}
/*
* Post-process command line flags.
*/
mced_debug_level = debug_level;
mced_log_events = log_events;
if (mced_debug_level > 0) {
foreground = 1;
}
if (max_interval_ms <= 0) {
max_interval_ms = -1;
}
if (min_interval_ms < 0) {
min_interval_ms = 0;
}
if (clientmax < 0) {
clientmax = 0;
}
if (overflow_suppress_time < 0) {
overflow_suppress_time = 0;
}
if (mce_rate_limit <= 0) {
mce_rate_limit = -1;
}
if (socketfile_compat && socketfile_compat[0] == '\0') {
socketfile_compat = MCED_SOCKETFILE_V1;
}
return 0;
}
/*
* Helper function for handling '-h' cmdlines.
*/
static void
do_help(const struct cmdline_opt *opt __attribute__((unused)), ...)
{
usage(stdout);
exit(EXIT_SUCCESS);
}
/*
* Helper function for handling '-v' cmdlines.
*/
static void
do_version(const struct cmdline_opt *opt __attribute__((unused)), ...)
{
printf(PACKAGE "-" PRJ_VERSION "\n");
exit(EXIT_SUCCESS);
}
static void
close_fds(void)
{
int fd, max;
max = sysconf(_SC_OPEN_MAX);
for (fd = 3; fd < max; fd++)
close(fd);
}
static int
daemonize(void)
{
switch(fork()) {
case -1:
mced_log(LOG_ERR, "ERR: fork: %s\n", strerror(errno));
return -1;
case 0:
/* child */
break;
default:
/* parent */
exit(EXIT_SUCCESS);
}
/* disconnect */
setsid();
umask(0);
/* get out of the way */
if (chdir("/") < 0) {
mced_log(LOG_ERR, "ERR: chdir(\"/\"): %s\n", strerror(errno));
return -1;
}
return 0;
}
static int
open_log(void)
{
int nullfd;
int log_opts;
int ret;
/* open /dev/null */
nullfd = open("/dev/null", O_RDWR);
if (nullfd < 0) {
mced_log(LOG_ERR, "ERR: can't open /dev/null: %s\n",
strerror(errno));
return -1;
}
log_opts = LOG_CONS|LOG_NDELAY;
if (mced_debug_level > 0) {
log_opts |= LOG_PERROR;
}
openlog(PACKAGE, log_opts, LOG_DAEMON);
/* set up stdin, stdout, stderr to /dev/null */
ret = 0;
if (dup2(nullfd, STDIN_FILENO) != STDIN_FILENO) {
mced_log(LOG_ERR, "LOG_ERR: dup2: %s\n", strerror(errno));
ret = -1;
}
if (!mced_debug_level && dup2(nullfd, STDOUT_FILENO) != STDOUT_FILENO) {
mced_log(LOG_ERR, "ERR: dup2: %s\n", strerror(errno));
ret = -1;
}
if (!mced_debug_level && dup2(nullfd, STDERR_FILENO) != STDERR_FILENO) {
mced_log(LOG_ERR, "ERR: dup2: %s\n", strerror(errno));
ret = -1;
}
close(nullfd);
log_is_open = 1;
return ret;
}
static int
create_pidfile(void)
{
int fd;
/* JIC */
unlink(pidfile);
/* open the pidfile */
fd = open(pidfile, O_WRONLY|O_CREAT|O_EXCL, 0644);
if (fd >= 0) {
FILE *f;
/* write our pid to it */
f = fdopen(fd, "w");
if (f != NULL) {
fprintf(f, "%d\n", getpid());
fclose(f);
/* leave the fd open */
return 0;
}
close(fd);
}
/* something went wrong */
mced_log(LOG_ERR, "ERR: can't create pidfile %s: %s\n",
pidfile, strerror(errno));
return -1;
}
static void
clean_exit_with_status(int status)
{
mced_cleanup_rules(1);
#if ENABLE_MCEDB
mcedb_close(mced_db);
#endif
unlink(pidfile);
mced_log(LOG_NOTICE, "exiting\n");
exit(status);
}
static void
clean_exit(int sig)
{
mced_log(LOG_NOTICE, "caught signal %d\n", sig);
clean_exit_with_status(EXIT_SUCCESS);
}
static void
clean_exit_with_killer(int signum, siginfo_t *siginfo,
void __attribute__((unused)) *context) {
char fname[255];
char cmdline[1023];
int cmdline_success = 0;
mced_log(LOG_NOTICE, "caught signal %d\n", signum);
snprintf(fname, sizeof(fname)-1, "/proc/%u/cmdline", siginfo->si_pid);
FILE *cmdline_file = fopen(fname, "r");
if (cmdline_file) {
if (fgets(cmdline, 1023, cmdline_file)) {
cmdline_success = 1;
}
fclose(cmdline_file);
}
if (cmdline_success) { // file successfully read
mced_log(
LOG_NOTICE,
"killed by process with pid %u and command line %.1022s\n",
siginfo->si_pid,
cmdline);
} else {
mced_log(
LOG_NOTICE,
"killed by process with pid %u and unknown command line\n",
siginfo->si_pid);
}
clean_exit_with_status(EXIT_SUCCESS);
}
static void
reload_conf(int sig __attribute__((unused)))
{
mced_log(LOG_NOTICE, "reloading configuration\n");
mced_cleanup_rules(0);
mced_read_conf(confdir);
}
static int
mced_vlog(int level, const char *fmt, va_list args)
{
if (log_is_open) {
vsyslog(level, fmt, args);
} else {
vfprintf(stderr, fmt, args);
}
return 0;
}
int
mced_log(int level, const char *fmt, ...)
{
va_list args;
int r;
va_start(args, fmt);
r = mced_vlog(level, fmt, args);
va_end(args);
return r;
}
int
mced_debug(int min_dbg_lvl, const char *fmt, ...)
{
va_list args;
int r;
if (mced_debug_level < min_dbg_lvl) {
return 0;
}
va_start(args, fmt);
r = mced_vlog(LOG_DEBUG, fmt, args);
va_end(args);
return r;
}
int
mced_perror(int level, const char *str)
{
return mced_log(level, "%s: %s\n", str, strerror(errno));
}
static int
open_socket(const char *path, mode_t mode, const char *group)
{
int sock_fd;
sock_fd = ud_create_socket(path);
if (sock_fd < 0) {
mced_log(LOG_ERR, "ERR: can't open socket %s: %s\n",
path, strerror(errno));
return -1;
}
fcntl(sock_fd, F_SETFD, FD_CLOEXEC);
chmod(path, mode);
if (group) {
struct group *gr;
struct stat buf;
gr = getgrnam(group);
if (!gr) {
mced_log(LOG_ERR, "ERR: group %s does not exist\n",
group);
close(sock_fd);
return -1;
}
if (stat(path, &buf) < 0) {
mced_log(LOG_ERR, "ERR: can't stat %s\n", path);
close(sock_fd);
return -1;
}
if (chown(path, buf.st_uid, gr->gr_gid) < 0) {
mced_log(LOG_ERR, "ERR: chown(): %s\n",
strerror(errno));
close(sock_fd);
return -1;
}
}
return sock_fd;
}
/* convert a kernel MCE struct to our MCE struct */
static void
kmce_to_mce(struct kernel_mce *kmce, struct mce *mce)
{
struct timeval tv;
gettimeofday(&tv, NULL);
/* common fields for all versions of 'struct kernel_mce' */
mce->boot = bootnum;
mce->bank = kmce->bank;
mce->mci_status = kmce->status;
mce->mci_address = kmce->addr;
mce->mci_misc = kmce->misc;
mce->mcg_status = kmce->mcgstatus;
mce->tsc = kmce->tsc;
mce->cs = kmce->cs;
mce->ip = kmce->rip;
if (kernel_mce_version == KERNEL_MCE_V1) {
mce->time = (tv.tv_sec * 1000000ULL) + tv.tv_usec;
mce->cpu = kmce->cpu;
mce->socket = -1;
mce->vendor = VENDOR_UNKNOWN;
mce->cpuid_eax = 0;
mce->init_apic_id = (uint32_t)-1U;
mce->mcg_status = 0;
} else if (kernel_mce_version == KERNEL_MCE_V2) {
if (kmce->time != 0) {
mce->time = kmce->time * 1000000ULL;
} else {
mce->time = (tv.tv_sec * 1000000ULL) + tv.tv_usec;
}
mce->cpu = kmce->extcpu;
mce->socket = kmce->socketid;
mce->vendor = kmce->cpuvendor;
mce->cpuid_eax = kmce->cpuid;
mce->init_apic_id = kmce->apicid;
mce->mcg_status = kmce->mcgcap;
} else {
/* this should never happen */
mced_log(LOG_EMERG,
"FATAL: kernel_mce_version (%d) is unknown\n",
kernel_mce_version);
clean_exit_with_status(EXIT_FAILURE);
}
}
/* this is used in a few places to throttle messages */
struct rate_limit {
int initialized; /* first one been done? */
int period; /* milliseconds */
struct timeval last_time; /* last time we hit this */
};
#define RATE_LIMIT(ms) { \
.initialized = 0, \
.period = ms, \
.last_time = { 0, 0} \
}
/* subtract two timevals */
static int
elapsed_usecs(struct timeval *t0, struct timeval *t1)
{
int elapsed = (t1->tv_sec - t0->tv_sec) * 1000000;
elapsed += (t1->tv_usec - t0->tv_usec);
return elapsed;
}
/* do we need to apply rate limiting? */
static int
apply_rate_limit(struct rate_limit *limit)
{
struct timeval now;
int msecs_since_last;
if (!limit->initialized) {
/* first time through here, just remember it */
limit->initialized = 1;
gettimeofday(&limit->last_time, NULL);
return 0;
}
/* find how long it has been since the last event */
gettimeofday(&now, NULL);
msecs_since_last = elapsed_usecs(&limit->last_time, &now) / 1000;
/* has enough time elapsed? */
if (msecs_since_last < limit->period) {
/* rate limit */
return 1;
}
/* do not rate limit */
limit->last_time = now;
return 0;
}
/* process a single MCE */
static int
do_one_mce(struct kernel_mce *kmce)
{
struct mce mce;
static struct rate_limit hw_overflow_limit;
static int rate_limit_initialized = 0;
/* initialize the rate limits based on a commandline flag */
if (!rate_limit_initialized) {
rate_limit_initialized = 1;
hw_overflow_limit.period = overflow_suppress_time * 1000;
}
/* convert the kernel's MCE struct to our own */
kmce_to_mce(kmce, &mce);
/* check for overflow */
if ((mce.mci_status & MCI_STATUS_OVER)
&& (mced_log_events || !apply_rate_limit(&hw_overflow_limit))) {
mced_log(LOG_WARNING, "MCE overflow detected by hardware\n");
if (!mced_log_events && overflow_suppress_time) {
mced_log(LOG_WARNING,
"(previous message suppressed for %lld seconds)",
overflow_suppress_time);
}
}
#if ENABLE_MCEDB
if (mcedb_append(mced_db, &mce) < 0) {
mced_log(LOG_ERR,
"ERR: failed to append MCE to database - not good!!\n");
} else {
mced_debug(1, "DBG: logged MCE #%d\n", mcedb_end(mced_db)-1);
}
#endif
if (mced_log_events) {
mced_log(LOG_INFO, "starting MCE handlers\n");
}
mced_handle_mce(&mce);
if (mced_log_events) {
mced_log(LOG_INFO, "completed MCE handlers\n");
}
#if ENABLE_DBUS
if (!no_dbus) {
dbus_send_mce(&mce);
}
#endif
return 0;
}
/* get the MCE log length from the kernel */
static int
get_loglen(int mce_fd)
{
if (!fake_dev_mcelog) {
int loglen;
int r = ioctl(mce_fd, MCE_GET_LOG_LEN, &loglen);
if (r < 0) {
mced_perror(LOG_ERR, "ERR: ioctl(MCE_GET_LOG_LEN)");
return -1;
}
return loglen;
} else {
return 1;
}
}
/* add some usecs to a timeval */
static void
advance_time_usecs(struct timeval *tv, int adv_usecs)
{
uint64_t tv_us = (tv->tv_sec * 1000000) + tv->tv_usec + adv_usecs;
tv->tv_sec = tv_us / 1000000;
tv->tv_usec = tv_us % 1000000;
}
/* enforce MCE rate limiting */
static void
rate_limit_mces(void)
{
static int first_event = 1;
static struct timeval last_timestamp;
static int bias;
if (mce_rate_limit <= 0) {
/* no rate limiting */
return;
} else if (first_event) {
/* first time through here, just remember it */
first_event = 0;
gettimeofday(&last_timestamp, NULL);
} else {
/* we might have to rate limit */
struct timeval now;
int usecs_since_last;
int usecs_per_event = 1000000 / mce_rate_limit;
/* find how long it has been since the last event */
gettimeofday(&now, NULL);
usecs_since_last = elapsed_usecs(&last_timestamp, &now);
/* set the last_timestamp to now, we might change it later */
last_timestamp = now;
/* are we under the minimum time between events? */
if (usecs_per_event > usecs_since_last) {
int usecs_to_kill;
int missed_by;
/*
* We set the last_timestamp to the *ideal* time
* (now + usecs_to_kill), rather than the real
* time after the usleep(). This is because
* usleep() (and all other sleeps, really) is
* inaccurate with very small values. This gets
* us closer to the actual requested rate
* limiting.
*
* We also try to bias the sleep time based on
* past inaccuracy. We integrate the over/under
* deltas somewhat slowly, so large transients
* should not distort the bias too quickly.
*/
usecs_to_kill = usecs_per_event - usecs_since_last;
advance_time_usecs(&last_timestamp, usecs_to_kill);
if ((usecs_to_kill + bias) > 0) {
/* do the actual sleep */
usleep(usecs_to_kill + bias);
}
/* adjust the bias */
gettimeofday(&now, NULL);
missed_by = elapsed_usecs(&last_timestamp, &now);
bias -= missed_by / 8;
}
}
}
/* read and handle and MCEs that are pending in the kernel */
static int
do_pending_mces(int mce_fd)
{
int loglen;
int nmces = 0;
int flags = 0;
static struct rate_limit sw_overflow_limit;
static int rate_limit_initialized = 0;
/* initialize the rate limits based on a commandline flag */
if (!rate_limit_initialized) {
rate_limit_initialized = 1;
sw_overflow_limit.period = overflow_suppress_time * 1000;
}
/* check for MCEs */
loglen = get_loglen(mce_fd);
if (loglen > 0) {
uint8_t buf[mced_kernel_record_len*loglen];
int n;
/* read all of the MCE data */
n = read(mce_fd, buf, mced_kernel_record_len*loglen);
if (n < 0) {
if (fake_dev_mcelog && errno == EAGAIN) {
return 0;
}
mced_perror(LOG_ERR, "ERR: read()");
return -1;
}
/* did we get any MCES? */
nmces = n/mced_kernel_record_len;
if (nmces > 0) {
int i;
/* read the flags */
if (!fake_dev_mcelog
&& ioctl(mce_fd, MCE_GETCLEAR_FLAGS, &flags) < 0) {
mced_log(LOG_ERR, "ERR: can't get flags: %s\n",
strerror(errno));
return -1;
}
/* check for overflow */
if ((flags & MCE_FLAG_OVERFLOW)
&& (mced_log_events
|| !apply_rate_limit(&sw_overflow_limit))){
mced_log(LOG_WARNING,
"MCE overflow detected by software\n");
if (!mced_log_events
&& overflow_suppress_time) {
mced_log(LOG_WARNING,
"(previous message suppressed "
"for %lld seconds)",
overflow_suppress_time);
}
}
if (mced_log_events) {
mced_debug(1, "DBG: got %d MCE%s\n",
nmces, (nmces==1)?"":"s");
}
/* handle all the new MCEs */
for (i = 0; i < nmces; i++) {
struct kernel_mce kmce;
rate_limit_mces();
/* The assumption is that newer versions of
* 'struct kernel_mce' are guaranteed to be
* supersets of older versions. */
memcpy(&kmce, &buf[i*mced_kernel_record_len],
mced_kernel_record_len);
do_one_mce(&kmce);
}
}
}
return nmces;
}
/* see if poll() works on /dev/mcelog */
static int
check_mcelog_poll(int mce_fd)
{
if (!CHECK_FOR_NON_POLL_KERNELS) {
return 1;
}
// On a machine with a lot of errors, this loops forever!
while (1) {
int r;
struct pollfd ar[1];
/* try poll() on mcelog and see what happens */
ar[0].fd = mce_fd;
ar[0].events = POLLIN;
r = poll(ar, 1, 0);
if (r < 0) {
if (errno == EINTR) {
continue;
}
mced_perror(LOG_ERR, "ERR: poll()");
return 0;
}
/* if poll() reports a timeout, we assume it works */
if (r == 0) {
return 1;
}
/*
* If poll() reports data, we have to read it to find out
* if there is actually data, or if it is a bogus return.
* If we find data, we need to retry. We can't be sure
* poll() works unless we can trigger some behavior that
* is not present in non-poll() kernels. That's a
* timeout. If poll() reports data, but read() finds
* none, we can assume poll() does not work.
*/
if (ar[0].revents) {
if (ar[0].revents & POLLIN) {
if (do_pending_mces(mce_fd) > 0) {
continue;
}
} else {
mced_log(LOG_WARNING,
"odd, poll set flags 0x%x\n",
ar[0].revents);
}
}
break;
}
return 0;
}
static int
get_kernel_version(unsigned *vmajor, unsigned *vminor, unsigned *vmicro)
{
struct utsname u;
int r = uname(&u);
if (r < 0) {
return r;
}
r = sscanf(u.release, "%u.%u.%u", vmajor, vminor, vmicro);
if (r != 3) {
errno = EBADMSG;
return -1;
}
mced_debug(1, "DBG: found kernel %u.%u.%u\n",
*vmajor, *vminor, *vmicro);
return 0;
}
static int
init_kernel_mce_interface(int mce_fd)
{
if (fake_dev_mcelog) {
mced_kernel_record_len = sizeof(struct kernel_mce);
kernel_mce_version = KERNEL_MCE_V1;
} else {
int r;
/* Adjust for kernel versions. */
unsigned vmajor, vminor, vmicro;
r = get_kernel_version(&vmajor, &vminor, &vmicro);
if (r < 0) {
static int printed_msg;
if (!printed_msg) {
printed_msg = 1;
mced_perror(LOG_ERR,
"ERR: can't get kernel version\n");
}
return -1;
}
/* assume the historical kernel layout */
kernel_mce_version = KERNEL_MCE_V1;
/* there were layout changes in 2.6.31 */
if ((vmajor > 2)
|| (vmajor == 2 && vminor > 6)
|| (vmajor == 2 && vminor == 6 && vmicro >= 31)) {
kernel_mce_version = KERNEL_MCE_V2;
}
/* Figure out the kernel's 'struct mce' size. */
r = ioctl(mce_fd, MCE_GET_RECORD_LEN, &mced_kernel_record_len);